Is a 1.5hp Hayward Northstar pump sufficient for a 47000 gallon 24 x 48 pool with 2 skimmers 6 returns a 30 inch Hayward sand filter 1.5 inch pipes where the pump is 100 feet from the pool?

No. its not the pump, its the pipe size..That 1.5hp pump well only pump about 32psi (at sea level) but a large volume of water, a .5hp pump well also pump app. 32 psi but a smaller volume. Look at the filter it well have the total GPL (gallons per minute) then look at the pump it well have the pump curve.. Better yet, look up Hayward on the net and ask for the site for hydraulics, it well show you how to figure the right pump to the right filter to to total gallons..

Yes, this pump will do the job for you. This pump will easily do 37 GPM, 24 hours a day, which is what you will need, since you probably have 70-80 feet of head, due to 1.5 inch Plumbing. If you want to reduce the head losses, you will need to at least re-do the above ground plumbing to 2 inch diameter, especialy going to the pump.